A great number of spray guns are known. Among configurations of interest are the configurations illustrated and described in the following listed U.S. Pat. Nos. and published applications: 2003/0006322; 6,712,292; 6,698,670; 6,669,112; 6,572,029; 6,460,787; 6,402,058; RE36,378; 6,276,616; 6,189,809; 6,179,223; 5,836,517; 5,829,679; 5,803,313; RE35,769; 5,639,027; 5,618,001; 5,582,350; 5,553,788; 5,400,971; 5,395,054; D349,559; 5,351,887; 5,332,159; 5,332,156; 5,330,108; 5,303,865; 5,299,740; 5,289,974; 5,284,301; 5,284,299; 5,236,129; 5,209,405; 5,209,365; 5,178,330; 5,119,992; 5,118,080; 5,180,104; D325,241; 5,090,623; 5,074,466; 5,064,119; 5,054,687; D318,712; 5,022,590; 4,993,645; 4,934,607; 4,934,603; 4,927,079; 4,911,367; D305,453; D305,452; D305,057; D303,139; 4,844,342; 4,770,117; 4,760,962; 4,759,502; 4,747,546; 4,702,420; 4,613,082; 4,606,501; D287,266; 4,537,357; 4,529,131; 4,513,913; 4,483,483; 4,453,670; 4,437,614; 4,433,812; 4,401,268; 4,361,283; D270,368; D270,367; D270,180; D270,179; RE30,968; 4,331,298; 4,248,386; 4,214,709; 4,174,071; 4,174,070; 4,169,545; 4,165,022; D252,097; 4,133,483; 4,116,364; 4,114,564; 4,105,164; 4,081,904; 4,037,561; 4,030,857; 4,002,777; 4,001,935; 3,990,609; 3,964,683; and, 3,940,061. Reference is here also made to U.S. Pat. Nos.: 6,562,137; 6,423,142; 6,144,570; 5,978,244; 5,159,544; 4,745,520; 4,485,427; 4,481,557; 4,324,812; 4,187,527; 4,075,677; 3,894,272; 3,875,892; and, 3,851,618. The disclosures of these references are hereby incorporated herein by reference. This listing is not intended to be a representation that a complete search of all relevant art has been made, or that no more pertinent art than that listed exists, or that the listed art is material to patentability. Nor should any such representation be inferred.